The present invention relates to a method of protecting the equine hoof, promoting comfort and health thereof, and enhancing the biomechanical performance of the animal. More particularly, the present invention is a horseshoe composed of one or more plastic and other components which can be nailed or glued to the equine hoof.
An animal hoof and especially an equine hoof is composed of a relatively hard outer surface, a sole and other structures on the ground surface of the foot. The outer surface continues to grow during the animal's lifetime (similar to the human fingernail). In the wild, the growth rate of the hoof wall is approximately balanced by the wear processes as the animal moves. However, in a domestic horse, for example, such is not the case. Due to the use we humans make of the horse and the surfaces and conditions they are kept in, some ‘artificial’ treatment of the hoof is generally required. Most generally, a farrier will trim the hoof and apply a metal shoe to protect the foot. In recent years some non-metal shoes have also been introduced.
When the farrier trims the outer shape of the hoof, a large number of choices can be made concerning what the optimal shape of the hoof might be. Over the years, a great many theories, methodologies, and opinions concerning the best shape of the hoof have been and continue to be espoused. It is generally agreed that various angles, distances, thicknesses, and other measures of the hoof shape dramatically affect the motion, comfort, and, ultimately, health of the animal such as a horse. In perhaps a somewhat typical current practice, a farrier attends to a horse about every 6 weeks. The old shoes are removed, the hoofs are trimmed, and new shoes are placed on the feet.
A typical situation for domestic horse is that the ‘toe’ portion of the hoof grows out more quickly than the ‘heel’ portion of the hoof, and hence, without periodic trimming, the angle the foot makes with the ground (as seen from a side view) would gradually change. However, a great variety of other situations concerning the shape and growth of the hoof occur, and it is the job of the farrier, sometimes with a veterinarian's advice, to determine the best course of action to maintain the health and usefulness of the horse.
The shoeing of horses is a practice that dates back hundreds of years. Through most of the history of horse shoeing, materials such as plastic were not available, and so traditionally, steel has been used. Over the past many decades, although plastic has been available, the horse shoeing profession has been slow to adopt the use of plastic shoes. Most (if not all) of the plastic shoes introduced to date emulate the metal shoes closely. That is to say, other than switching to a plastic material, they have attempted to duplicate the function of a metal shoe. The present invention takes advantage of the properties of plastic and other design features to present a better shoe as regards animal comfort, health, and performance.
A number of factors regarding the equine hoof and the horse in nature are important to note. Firstly, the equine hoof is flexible. There is no reason to expect that constraining the hoof's flexibility by attaching it to a rigid metal shoe will promote health and comfort of the animal. Only in rare situations (certain injuries to the foot) would this form of immobilization be recommended. Secondly, in nature the underside (“sole”) of the equine hoof is generally packed with dirt in such a way that the weight of the animal is supported not only on the outer hard hoof wall, but also to some extent on the interior “sole” portion of the foot. Hence, the equine research community has come to believe that traditional attempts to bear all weight on the hoof wall, supported on a “rim” style shoe, may be a poor approach as regards long-term animal health, comfort, and performance. Thirdly; it is generally accepted that changes to the exterior shape geometry of the hoof (and shoes or other attachments) can and do affect the motion and static and dynamic weight-bearing of the horse. Traditional shoe designs, and even recent shoe designs, do not adequately take into account the way in which they affect the overall biomechanical functioning of the hoof and animal. In particular, details of the front shape of the shoe have an effect on how the toe “rolls over” or “breaks over” during a locomotion cycle. Fourthly, the ground surface of the shoe is an important consideration—horses need to slip slightly as they locomote, but they cannot slip too much. Just the right amount of stick and slip must be carefully considered. Finally, the method of attachment of the shoe to the foot may adversely affect the animal and must be considered in any shoe design.
Thus, there is a need for a shoe which is somewhat flexible in accordance with the material properties of the natural hoof. There is also a need for a shoe which emulates the sole support found in nature by the fact that dirt generally packs the foot.. There is also a need for a shoe which has a carefully considered geometric shape so as to minimally impact the natural biomechanical function of the animal. There is also a need for a shoe whose traction characteristics are well matched to the horse's motion so that the animal neither falls due to lack of traction, nor suffers undue leg and joint stresses caused by too much traction. Finally, there is a need for a good attachment scheme to attach the shoe to the foot.
Therefore, it would be desirable to have a shoe with several design features meant to address all of these concerns.